Omnisharp failing due to `System.IO.IOException: The process cannot access the file ... because it is being used by another process`

[bigyihsuan]

Issue Description

When saving a C# file (/filesChanged), Omnisharp fails due to a System.IO.IOException, stating that it is being used by another process.

Steps to Reproduce

1. Create a new project.
2. Have Omnisharp set to format on save.
3. Make changes to a C# file.
4. Save or otherwise trigger the /filesChanged command.

Expected Behavior

The C# file should be formatted and saved.

Actual Behavior

The file does not get formatted, and the output log prints the log below.

Logs

OmniSharp log

[warn]: OmniSharp.Stdio.Host
        ************ Request ************
{
  "Type": "request",
  "Seq": 180,
  "Command": "/filesChanged",
  "Arguments": [
    {
      "FileName": "d:\\Programming\\GithubRepos\\CsLorax\\LoraxTest\\LoraxTest.cs",
      "changeType": "Change"
    }
  ]
}
[fail]: OmniSharp.Stdio.Host
        ************  Response (0.7794ms) ************ 
{
  "Request_seq": 180,
  "Command": "/filesChanged",
  "Running": true,
  "Success": false,
  "Message": "\"System.IO.IOException: The process cannot access the file 'd:\\\\Programming\\\\GithubRepos\\\\CsLorax\\\\LoraxTest\\\\LoraxTest.cs' because it is being used by another process.\\r\\n   at Microsoft.Win32.SafeHandles.SafeFileHandle.CreateFile(String fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options)\\r\\n   at Microsoft.Win32.SafeHandles.SafeFileHandle.Open(String fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize)\\r\\n   at System.IO.Strategies.OSFileStreamStrategy..ctor(String path, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize)\\r\\n   at System.IO.Strategies.FileStreamHelpers.ChooseStrategy(FileStream fileStream, String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, Int64 preallocationSize)\\r\\n   at System.IO.StreamReader.ValidateArgsAndOpenPath(String path, Encoding encoding, Int32 bufferSize)\\r\\n   at System.IO.File.InternalReadAllText(String path, Encoding encoding)\\r\\n   at System.IO.File.ReadAllText(String path)\\r\\n   at OmniSharp.Roslyn.BufferManager.UpdateBufferAsync(Request request, Boolean isCreate) in D:\\\\a\\\\1\\\\s\\\\src\\\\OmniSharp.Roslyn\\\\BufferManager.cs:line 49\"",
  "Body": null,
  "Seq": 3960,
  "Type": "response"
}

C# log

Getting latest OmniSharp version information
Downloading package 'Latest OmniSharp Version Information' (1 KB).................... Done!

Environment information

VSCode version: 1.67.2 C# Extension: 1.25.0

Dotnet Information

.NET SDK (reflecting any global.json): Version: 6.0.201 Commit: ef40e6aa06

Runtime Environment: OS Name: Windows OS Version: 10.0.19044 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\6.0.201\

Host (useful for support): Version: 6.0.3 Commit: c24d9a9c91

.NET SDKs installed: 5.0.406 [C:\Program Files\dotnet\sdk] 6.0.201 [C:\Program Files\dotnet\sdk]

.NET runtimes installed: Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 5.0.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 6.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 3.1.23 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 5.0.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 6.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.WindowsDesktop.App 3.1.23 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 5.0.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 6.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs: https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
autodocstring	njpwerner	0.6.1
better-comments	aaron-bond	3.0.0
better-cpp-syntax	jeff-hykin	1.15.14
better-shellscript-syntax	jeff-hykin	1.1.0
better-toml	bungcip	0.3.2
blazorwasm-companion	ms-dotnettools	1.1.0
copilot	GitHub	1.24.6022
cpptools-themes	ms-vscode	1.0.0
csharp	ms-dotnettools	1.25.0
csharpextensions	jchannon	1.3.1
dark-plus-material	vangware	3.0.4
errorlens	usernamehw	3.5.1
es7-react-js-snippets	dsznajder	4.4.3
format-html-in-php	rifi2k	1.7.0
html-preview-vscode	tht13	0.2.5
indent-rainbow	oderwat	8.3.1
java	redhat	1.6.0
JavaScriptSnippets	xabikos	1.8.0
jshint	dbaeumer	0.11.0
jupyter	ms-toolsai	2022.4.1021342353
jupyter-keymap	ms-toolsai	1.0.0
jupyter-renderers	ms-toolsai	1.0.8
kotlin	fwcd	0.2.26
Kotlin	mathiasfrohlich	1.7.1
ksp-cfg-support	al2me6	0.2.1
lexurgy-syntax-highlighting	bigyihsuan9999	0.0.2
Lisp	mattn	0.1.12
markdown-all-in-one	yzhang	3.4.3
markdown-mermaid	bierner	1.14.0
markdown-pdf	yzane	1.4.4
markdown-preview-enhanced	shd101wyy	0.6.3
material-theme	zhuangtongfa	3.13.29
mayukaithemevsc	GulajavaMinistudio	3.2.1
mermaid-markdown-syntax-highlighting	bpruitt-goddard	1.2.3
noctis	liviuschera	10.40.0
one-dark-pro-monokai-darker	eserozvataf	1.1.0
one-dark-theme	mskelton	1.14.2
one-monokai	azemoh	0.5.0
pdf	tomoki1207	1.2.0
php-debug	xdebug	1.26.1
php-intellisense	zobo	1.0.8
php-pack	xdebug	1.0.3
prettify-json	mohsen1	0.0.3
python	ms-python	2022.6.3
rainbow-csv	mechatroner	2.4.0
rainbow-tags	voldemortensen	0.4.1
red-one-dark-pro	giladgd	1.5.0
remote-containers	ms-vscode-remote	0.234.0
remote-ssh	ms-vscode-remote	0.80.0
remote-ssh-edit	ms-vscode-remote	0.80.0
remote-wsl	ms-vscode-remote	0.66.3
rust	rust-lang	0.7.8
rust-analyzer	rust-lang	0.3.1075
rust-syntax	dustypomerleau	0.6.0
semantic-rainbow	thertzlor	1.0.5
shebang-snippets	rpinski	0.1.4
sql-snippet	Miladfathy	0.0.4
sql-snippets	sadeghpm	0.0.4
syntax-highlight	peaceshi	0.0.14
teppz	ofrades	2.4.2
vsc-community-material-theme	Equinusocio	1.4.4
vsc-material-theme	Equinusocio	33.4.0
vsc-material-theme-icons	equinusocio	2.3.1
vsc-moonrise-theme	odind	0.2.2
vscode-antlr4	mike-lischke	2.3.0
vscode-color-identifiers-mode	MatthewNespor	1.2.0
vscode-csharp-snippets	jorgeserrano	1.1.0
vscode-dotnet-runtime	ms-dotnettools	1.5.0
vscode-ebnf	OMKOV	1.0.4
vscode-html-css	ecmel	1.12.2
vscode-icons	vscode-icons-team	11.12.0
vscode-intelephense-client	bmewburn	1.8.2
vscode-java-debug	vscjava	0.41.0
vscode-java-dependency	vscjava	0.19.1
vscode-java-pack	vscjava	0.22.4
vscode-java-test	vscjava	0.35.0
vscode-JS-CSS-HTML-formatter	lonefy	0.2.3
vscode-markdownlint	DavidAnson	0.47.0
vscode-maven	vscjava	0.35.2
vscode-mysql-client2	cweijan	5.3.7
vscode-nuget-package-manager	jmrog	1.1.6
vscode-osgi	lgdd	1.0.2
vscode-pull-request-github	GitHub	0.42.0
vscode-pylance	ms-python	2022.5.3
vscode-remote-extensionpack	ms-vscode-remote	0.21.0
vscode-rusty-onedark	Jeraldson	1.0.3
vscode-solution-explorer	fernandoescolar	0.4.5
vscodeintellicode	VisualStudioExptTeam	1.2.21

[DanteMarshal]

I have a similar problem, except that save on format is not enabled in my case. Any workarounds yet ?

[Periapsises]

I have the same issue, and as @DanteMarshal pointed out, I don't have format on save enabled either. But otherwise, the error message is exactly the same. I'm using .NET SDK Version: 6.0.307 Commit: 55b7c993a1

I also saw this issue that has been marked as completed but the error message from this one is slightly different.

My only solution right now is to use the Restart OmniSharp command, but the error usually happens again soon after.. If anyone has a solution of info on this problem that would be fantastic :)